Reference: Reported in Tabaqaatul-Hanaabilah – Volume 2, Page 44 and Manhajul-Ahmad
Sharhus-Sunnah – Imaam al-Barbahaaree
Imaam al-Barbahaaree (rahima-hullaah) mentions:
The innovators are like scorpions.
They bury their heads and bodies in the sand and leave their tails out.
When they get the chance they sting; the same with the innovators who conceal themselves amongst the people, when they are able, they do what they desire.